JPH11142804A - Liquid crystal display - Google Patents

Abstract

(57) [Problem] To provide a liquid crystal display device using a light valve which is easy to set up and always provides uniform luminance and chromaticity. SOLUTION: In a liquid crystal display device using a combination of a light source 3, a liquid crystal projector 31 composed of a liquid crystal panel 16 and a projection lens 21, a total reflection mirror 27 is provided between the liquid crystal panel 16 and the projection lens 21. Means for moving the total reflection mirror 27, means for detecting the chromaticity and luminance of the light from the light valve after the movement, means for correcting the chromaticity of the light from the detected light to desired chromaticity, There is provided a means for correcting the luminance based on the information. When the chromaticity and the luminance are detected, the total reflection mirror 27 is moved by a simple mechanism in a small space in the liquid crystal projector to correct the chromaticity and the luminance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device used as a multivision by combining at least two liquid crystal projectors.

[0002]

2. Description of the Related Art In recent years, as a large-screen image display device, a multi-vision system in which a plurality of rear-integrated CRT projectors can be stacked and a single screen is displayed on the plurality of CRT projectors has been widely used. It is often used in public facilities such as stations. In these general systems, a video signal or a computer signal is divided by an image enlarging device into images corresponding to the number of projectors in the system configuration, and each image is received. This is a system that can display video signals and combine them to realize one large screen.

[0003]

However, in a conventional CRT type projector, it is necessary to drive each of the CRTs for red, blue and green to display colors. It was necessary to adjust the convergence of blue and green.

In order to solve the above problems, multi-vision systems using liquid crystal have been studied by various companies. However, the life of a light source lamp used in a projection engine is limited to a CR.
There is a problem that the brightness and chromaticity are shorter than T and the brightness and chromaticity change according to the use time.

Japanese Patent Laid-Open Publication No. Hei 6-148624 discloses that the lighting time of a lamp is stored in a memory and the color temperature is adjusted in accordance with the lighting time. It is not possible to manage chromaticity only by managing time. Furthermore, since multiple units are used in a stack, even a small variation in brightness and white balance can not achieve a uniform large screen, and the adjustment must take a very long time. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a liquid crystal display device using a combination of a plurality of liquid crystal projectors comprising a light source, a light valve and a projection lens. A means for moving the total reflection mirror between the lens and the lens, a means for detecting chromaticity and luminance of light from the light valve after the movement, and a chromaticity information of the detected light. A liquid crystal display device comprising: means for correcting a chromaticity to a desired chromaticity, and means for correcting luminance based on the luminance information.

[0007] Further, a reflection mirror having a reflectance of 90% or less is provided between the light valve and the projection lens, and means for detecting chromaticity and luminance is provided on the back surface of the reflection mirror. A liquid crystal display device comprising: means for correcting a desired chromaticity based on chromaticity information of light; and means for correcting luminance based on the luminance information.

The present invention further comprises means for controlling the transmission or diffusion of light from the light valve between the light valve and the projection lens, and then controlling the diffusion of light from the light valve to achieve chromaticity. A liquid crystal display device comprising: means for detecting brightness and a means for correcting brightness to a desired chromaticity based on the chromaticity information of the detected light; and means for correcting brightness based on the brightness information. .

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display device using a plurality of liquid crystal projectors each comprising a light source, a light valve and a projection lens, and a total reflection mirror is provided between the light valve and the projection lens. Have,
Means for moving the total reflection mirror, then means for detecting the chromaticity and luminance of the light from the light valve after the movement, means for correcting the chromaticity information of the detected light to a desired chromaticity, It is characterized by having a means for correcting the luminance based on the luminance information, and the total reflection mirror can be moved by a simple mechanism in a small space in the liquid crystal projector when the chromaticity and luminance are detected. There is an effect that light from the light valve can be detected by the detecting means and corrected to desired chromaticity and luminance.

In addition, a reflection mirror having a reflectance of 90% or less is provided between the light valve and the projection lens, and a means for detecting chromaticity and luminance is provided on a back surface of the reflection mirror, and the detection is performed. It is characterized by comprising a means for correcting to a desired chromaticity based on chromaticity information of light and a means for correcting luminance based on the luminance information, so that chromaticity and luminance detection can always be detected even during normal operation. At the same time, it is possible to perform detection without providing a mechanical moving means, and to provide a low-cost liquid crystal projector, and to always have a high-precision white balance and a high brightness.

The present invention further comprises means for controlling the transmission or diffusion of light from the light valve between the light valve and the projection lens, and then controlling the diffusion of light from the light valve to achieve chromaticity. And means for detecting the brightness, and means for correcting to a desired chromaticity by the chromaticity information of the detected light, and a means for correcting the brightness by the brightness information, characterized in that, At the time of chromaticity and luminance detection, light is diffused and detected. However, at the time of normal use, all light is transmitted, so that there is an effect that projection light from the light valve is not lost at all.

Hereinafter, embodiments of the liquid crystal display device of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram of a liquid crystal display device of the present invention.

A projection engine 30 is built in the main body 31 of the liquid crystal projector, and images formed on liquid crystal panels 16R, 16G and 16B in the engine are enlarged and projected by the projection lens 21 and projected on the surface of the screen 18. I do. A chromaticity / luminance sensor 36 is provided in the projection engine 30.
Is installed.

On the rear surface of the liquid crystal projector main body 31, a composite video input signal terminal (1) 32, an RGB input signal terminal (2) 37 and a data receiving section for exchanging information for equalizing luminance and chromaticity of a plurality of screens. 38 and a data transmission unit 39. In this embodiment, two vertical units × two horizontal units
A description will be given of a four-screen multi-vision system. However, as long as there are at least two or more, the same implementation can be performed in a system of one vertical × two horizontal or three vertical × four horizontal. FIG. 2 is a configuration diagram of the projection engine 30 built in the liquid crystal projector main body 31.

The light emitted from the metal halide lamp 1 is converted by the parabolic mirror 2 into parallel light. The parallel light from the light source 3 is blocked by the ultraviolet / infrared cut filter 4 from transmitting ultraviolet and infrared rays to the front surface, and then enters the color separation means 8. The color separation means 8 separates white light from a light source into blue, green, and red color lights by the blue reflection dichroic mirror 5 and the green reflection dichroic mirror 6. The blue, green, and red color lights separated by the color separation means 8 pass through the field lens 9 and enter the λ / 2 plates 10, 11, and 12. λ / 2 plate is generally circularly polarized light, reverse of elliptically polarized light,
Used for azimuth conversion of linearly polarized light. λ / 2 plate 10,
Reference numerals 11 and 12 are arranged to control the spectral distribution of linearly polarized color light used by the liquid crystal panel 16. λ / 2 plate 1
Light emitted from 0, 11, and 12 is incident on the liquid crystal panel 16 to transmit a display image on the liquid crystal panel 16. The light combining means 24 combines the respective display lights with blue light and green light with the green reflecting dichroic mirror 22, and then combines red, blue and green with the red reflecting dichroic mirror 23, and finally displays the display image of each liquid crystal panel 16. Is reflected by the total reflection mirror 27, and is enlarged and projected using the projection lens 21. On the other hand, the chromaticity / luminance sensor 36 is disposed on the optical axis of the light combining means 24 of the projection engine 30, and the transmitted light of the liquid crystal panel 16 is transmitted only when the total reflection mirror 27 is rotated around the fulcrum 28. 27.

FIG. 4 shows the spectral transmittance characteristics of the dichroic mirror 5 used in the present invention. Here, the solid line is the P-polarized light component, the one-dot chain line is the S-polarized light component, and the dotted line is the characteristic of the average value component of the P-polarized light and the S-polarized light of the dichroic mirror 5 used in the present invention. By rotating the λ / 2 plates 10, 11, and 12, the liquid crystal panels 16R, 16G, and 16B can use the color light in the range from the P-polarized component to the S-polarized component, so that the desired chromaticity can be finally adjusted.

In the above configuration, the operation will be described. During normal projection, the liquid crystal panels 16R, 16R
After the images displayed on G and 16B are combined by the color combining means 24, they are reflected by the total reflection mirror 25 and projected on the screen 18 by the projection lens 21. On the other hand, when performing chromaticity / luminance correction, the total reflection mirror 27 rotates around the fulcrum 28 and the chromaticity / luminance sensor operates to detect the chromaticity and luminance of the projection engine 30. Similarly, chromaticity and luminance are detected in all the liquid crystal projectors A to D, and the luminance is adjusted by adjusting the drive voltage of the liquid crystal panel 16 in the other projectors according to the lowest luminance. Further, regarding the chromaticity, the molecular orientation directions on the incident light side and the output light side of the liquid crystal cell 14 are at an angle θ with respect to the horizontal axis.
And the polarization axis (transmission axis) of the incident-side polarizing plate is provided so as to coincide with this direction. The angle between the neutral axis of the λ / 2 plate and the polarization axis of the incident side polarizing plate is θ / 2
By arranging in such a manner, the polarization axis direction of the incident side polarizing plate can be made to coincide with the P polarization direction of the dichroic mirror.

Accordingly, by arranging the λ / 2 plates 10, 11, and 12 in this manner, an optical image is formed by using light transmitted through the incident-side polarizing plate and used by the liquid crystal panel as color light of the P-polarized component of the dichroic mirror. I can do it. On the other hand, the angle between the neutral axis of the λ / 2 plate and the polarization axis of the incident side polarizing plate is (90 ° + θ)
By arranging such that the ratio becomes / 2, the polarization axis direction of the incident-side polarizing plate can be made to coincide with the S-polarization direction of the dichroic mirror. By arranging the λ / 2 plate in this manner, an optical image can be formed by using light transmitted through the incident-side polarizing plate and used in the liquid crystal panel as S-polarized light of the dichroic mirror. Therefore, by rotating the neutral axis of the minimum λ / 2 plate with respect to the horizontal axis so that the neutral axis can be arbitrarily set in the range of θ / 2 to (90 ° + θ) / 2, the liquid crystal panel 16 can rotate the P polarization component. Since the chromaticity and the luminance can be adjusted, the chromaticity and the luminance can be adjusted.
Therefore, the spectral characteristics of the light source 3 and the dichroic mirror 5
It is possible to easily achieve the desired adjustment even if the spectral transmittance characteristics vary, and to move the total reflection mirror 25 with a simple mechanism in a small space in the projection engine 30 when detecting chromaticity and luminance. The light from the photosynthesis means 24 can be directly detected.

FIG. 3 also shows a liquid crystal projector body 3.
In the configuration diagram of the projection engine 30 incorporated in 1, the light source 3, the color separation means 8, and the color synthesis means 24 are the same as those in FIG. The light obtained by the color synthesizing means 24 is reflected by a reflecting mirror 27 having a reflectance of 90% or less, and the projection lens 2
1 The reflection mirror 29 transmits the remaining light that is not reflected, and is used as detection light by a chromaticity / luminance sensor 36 as chromaticity / luminance detecting means. Here, the reflectance of the reflection mirror 29 is determined by the detection capability of the chromaticity / luminance sensor 36. In the present invention, 85% and 90% were experimentally determined.
It has been confirmed that there is no problem with the detection capability of the chromaticity / luminance sensor 36 in the reflection mirror 29 of the above. However, it is needless to say that if the reflectance of the reflection mirror 29 is too low, the luminance of the projection light is lost. . However, chromaticity and luminance can always be detected even during normal operation, and can be detected without a mechanical moving means, so that the low-cost liquid crystal projector 31 can always match high-precision white balance and luminance. .

(Embodiment 2) FIG. 5 is a system diagram of a rear surface of a liquid crystal projector in a four-screen multi-vision system according to an embodiment of the present invention. The signal from the data transmission unit 39 of the reference projector A is input to the data reception unit 38 of the projector D, and then the signal of the data transmission unit 39 of the projector D is transmitted to the data reception unit 38 of the projector C.
The signal of the data transmission unit 39 of the projector C is input to the data reception unit 38 of the projector B, and the signal of the data transmission unit 39 of the projector B is input to the data reception unit 38 of the projector A. It has become recognizable. As is clear from this system diagram, the reference projector is the same for all projectors. Although not shown, a dip switch or the like is provided in the projector body to determine which projector is to be used as the reference. Can be done.

FIG. 6 is a block diagram of the projection engine according to the embodiment of the present invention. The projection engine 30 built in the liquid crystal projector main body 31 includes the light source 3, the color separation means 8, and the color synthesis means 24, and has the same configuration as that of FIG. The light obtained by the color synthesizing means 24 is applied to the light diffusion / transmission rotary plate 4.
In the case of chromaticity and luminance correction, the light is diffused on a diffusion surface to detect and correct the light. In normal operation, almost 100% of the light is transmitted through the transmission surface and projected from the projection lens 21.

FIG. 7 is a structural view of the light diffusion / transmission rotary plate 40. The rotary plate has a semicircle as a diffusion surface and the remaining semicircle as a transmission surface, and can be rotated about the center as an axis. .

Next, a method of a luminance / chromaticity detecting means, a chromaticity correcting means, a means for transmitting / receiving luminance information, and a luminance correcting means will be described with reference to FIGS. 1, 5, 6 and 7. First, the power button of the liquid crystal projector main body 31 (not shown) is turned on, and the lamp 1 is turned on. Since the luminance and chromaticity of the lamp 1 are not stable for 2 minutes after lighting, the measurement is not performed. However, the diffusion surface of the light diffusion / transmission rotary plate 40 is placed on the optical path, and a 100% white signal is obtained by the internal test signal. And red, blue, green single color 100
% Signals are sequentially projected. After a lapse of two minutes, the luminance / chromaticity sensor 36 is operated, and measurement is performed using diffused light.

Next, a chromaticity / luminance information request signal is transmitted from the data transmission section 39 of the projector A set as the reference projector so as to loop to all the projectors. In the received projector D, the identification code 1 of the projector D is added to the header of the chromaticity / luminance information measured in advance.
1 (binary number) is transmitted from the data transmission unit 39 of the projector D to the data reception unit 38 of the projector C. Similarly, the projector C adds the identification code 10 (binary number) of the projector C to the header of the chromaticity / luminance information, and transmits the data of the projectors D and C from the data transmission unit 39 of the projector C to the data reception unit 38 of the projector B.
Send to Similarly, the projector B also adds the identification code 01 (binary number) of the projector B to the header of the chromaticity / luminance information, and transmits the data of the projectors D, C, and B from the data transmission unit 39 of the projector B to the projector A.
Is transmitted to the data receiving unit 38.

The reference projector A determines the lowest luminance value including its own chromaticity luminance data and the optimum chromaticity value. Next, the reference projector A transmits the identification code of the projector to be corrected and the correction data after the identification code 11111 (binary number) indicating the correction. In the received projector, the amplitude of the input level is adjusted to correct the brightness, and the λ / 2 plates 10, 11, and 12 are respectively rotated by motor control, and the liquid crystal panel 16 is turned from the P-polarized component to the S-polarized light.
The color light in the range of the polarization component can be used, and the chromaticity of a plurality of units can be uniformly adjusted.

As described above, even if there is variation in the spectral characteristics of the light source lamp 1 in the projection engine 30 or in the spectral transmittance characteristics of the dichroic mirror, the polarization axis selecting means of the λ / 2 plate is rotated to change the brightness and color. The degree can be automatically adjusted, and the brightness and chromaticity of the entire screen composed of a plurality of projectors can always be made uniform. Further, when detecting chromaticity and luminance, the light is diffused and detected, but during normal use, all light is transmitted, so that the projected light from the light valve is not lost at all.

[0028]

As is clear from the above description, the liquid crystal display device of the present invention is a liquid crystal display device using a combination of a plurality of liquid crystal projectors each comprising a light source, a light valve and a projection lens. A means for moving the total reflection mirror between the projection lens and the total reflection mirror; and a means for detecting chromaticity and luminance of light from the light valve after the movement, and a color of the detected light. Means for correcting the chromaticity to a desired chromaticity, and means for correcting the luminance based on the luminance information. When the chromaticity and luminance are detected, the total reflection mirror can be simplified in a small space in the liquid crystal projector. It has the characteristic that it can be moved by a mechanism and the light from the light valve can be directly detected by the detecting means and corrected to the desired chromaticity and luminance.

Further, a reflection mirror having a reflectance of 90% or less is provided between the light valve and the projection lens, and a means for detecting chromaticity and luminance is provided on a back surface of the reflection mirror, and the detection is performed. It is provided with a unit for correcting the chromaticity of light to a desired chromaticity and a unit for correcting the luminance based on the luminance information. A low-cost liquid crystal projector that can be detected without moving means,
It has the feature that it is possible to always match the white balance with high precision and luminance.

The present invention further comprises means for controlling the transmission or diffusion of light from the light valve between the light valve and the projection lens, and then controlling the diffusion of light from the light valve to achieve chromaticity. And means for detecting the luminance, and a means for correcting the chromaticity of the detected light to a desired chromaticity, and a means for correcting the luminance based on the luminance information. Is diffused and detected, but during normal use all light is transmitted, so that the projection light from the light valve is not lost at all, and the industrial value of the present invention is extremely large.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a projection engine according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a projection engine according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a spectral transmittance characteristic of the dichroic mirror according to the first embodiment of the present invention.

FIG. 5 is a transmission / reception system diagram in a four-screen multi-vision system according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a projection engine according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a light diffusion / transmission rotation plate according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Parabolic mirror 3 Light source 4 Ultraviolet / infrared cut filter 5, 6, 7, 22, 23 Dichroic mirror 8 Color separation means 9 Field lens 10, 11, 12 λ / 2 plate 13, 15 Polarizer 14 Liquid crystal cell Reference Signs List 16 liquid crystal panel 18 screen 21 projection lens 24 color synthesizing means 25, 26 mirror 27 total reflection mirror 28 fulcrum 29 90% reflection mirror 30 projection engine 31 projector main body 32 input signal terminal 1 36 chromaticity, luminance sensor 37 input signal terminal 2 38 Data transmitter 39 Data receiver 40 Light diffusion / transmission rotary plate

Claims (3)

[Claims] 1. A liquid crystal display device using a combination of a plurality of liquid crystal projectors each comprising a light source, a light valve and a projection lens, comprising: a total reflection mirror between the light valve and the projection lens; Means for moving the mirror, then means for detecting the chromaticity and luminance of the light from the light valve after the movement, means for correcting the chromaticity of the detected light to a desired chromaticity, and A liquid crystal display device comprising means for correcting luminance. 2. A liquid crystal display device using a light source, a plurality of liquid crystal projectors comprising a light valve and a projection lens in combination, and a reflection mirror having a reflectance of 90% or less between the light valve and the projection lens. A means for detecting chromaticity and luminance on the back of the reflection mirror, a means for correcting the chromaticity of the detected light to a desired chromaticity, and a means for correcting the luminance by the luminance information A liquid crystal display device comprising: 3. A liquid crystal display device using a plurality of liquid crystal projectors comprising a light source, a light valve and a projection lens in combination, wherein transmission or diffusion of light from the light valve between the light valve and the projection lens. A means for controlling the diffusion of light from the light valve to detect chromaticity and luminance, and a means for correcting the chromaticity information of the detected light to a desired chromaticity, A liquid crystal display device, comprising: means for correcting luminance based on luminance information.